This study will have two components. The first will be the determination of the feasibility of performing cost-effectiveness analyses for several health screening procedures. The second will be the actual analyses for those medical procedures. Preventive medicine is a topic much in vogue today, though the lines of discussion are often inconsistent with one another. The general public and segments of the medical community believe in the efficacy of disease prevention and such services as the annual check-up. Other segments of the medical community, however, are more skeptical of the effectiveness of routine screening, point out that check-ups probably need not be performed annually on symptom-free individuals. Joining the debate now are policymakers considering national health insurance. It is acknowledged that our present system of health insurance favors hospital (and hence crisis) care rather than ambulatory (including preventive) care. In all likelihood this imbalance will be altered by pending legislation, though we do not know the cost-effectiveness of added resources being directed toward preventive and screening services. Additional information is needed on the worthwhileness of many tests (and especially epidemiological) sources will be studied and combined with analyses of economic parameters for a large number of diseases to which periodic health screening is often directed. This study of cost-effectiveness will be of great value in indicating to the medical and lay communities the relative effectiveness and economic justification of health screening. Additionally, the study will be useful in designing a preventive care component of National Health Insurance which will utilize most effectively society's scarce health resources.